Hammer is one of the core components, which is arranged in the rotor shaft, hammer crusher at high speed in a direct blow to the material, eventually breaking into the appropriate particle size.
Hammer manufacturing process is a key factor to determine hammer’s life. If the manufacture of surface or internal defects such as shrinkage, cracks, transgranular, etc.will not only reduce hammer performance and even cause the hammer break. Thus, in the hammer must develop a reasonable production casting and heat treatment process. Hammer heat treatment process is determined to achieve the mechanical properties of the carbide distribution and morphology. As the hammer components contain a certain amount of chromium and other alloying elements, so how to make these alloying elements to form hard carbide particles into full play the role, but also the heat treatment process to develop a factor to consider. In short, to develop a reasonable production process and strict quality control measures is to ensure the hammer a prerequisite to performance. Crusher hammer according to the manufacturing process can be divided into two types: casting and forging, these two very different degree of wear.
The greater the hardness of the hammer ，the greater wear resistance of the hammer. To improve the wear resistance of the hammer, it is necessary to increase its hardness, but with improved hardness, toughness will reduce the impact hammer. Therefore, how to balance the hammer suitable hardness and good impact toughness is the key to improve the wear resistance of the hammer. Hammer commonly used materials are: high manganese steel, high chromium cast iron, carbon steel. High manganese steel toughness, good technology, low price, its main feature is the large impact or contact stress under the action of the surface layer will quickly produce hardening, the hardening index 5-7 times higher than other materials, wear resistance is greatly improved. However, if the impact is not enough towels, or use the contact stress is small, the surface can not quickly produce hardening, the wear resistance of high manganese steel can not be fully realized. High chromium cast iron is an excellent anti-wear performance of wear-resistant materials, but the toughness is low, prone to brittle fracture. For safe operation of high chromium cast iron hammer, it has developed a composite hammer, about the high chromium cast iron cast-in high-manganese steel or low alloy steel hammer head, hammer, or working part of high chromium cast iron, hammer handle part is carbon steel, the two combined, so that the hammer head has a high hardness and high toughness hammer shank, give full play to the respective advantages of two materials to overcome the shortcomings of a single material, use the hammer to meet the performance requirements. But its complex manufacturing process, more stringent process requirements. Mainly carbon steel with chromium, molybdenum and other elements of the alloy structure steel, high hardness, good toughness. Quenching and tempering heat treatment, but the hammer is the key, after quenching and tempering heat treatment requires not only the overall tensile strength of 850 MPa or more, and requires considerable plasticity and toughness.
Different structure and geometry of the hammer, the mechanical properties of heat, the internal microstructure is very different, and thus have a greater impact on the wear resistance, especially in thickness, large size of the hammer impact is more prominent . More Heavy hammer, the more difficult to hardenability, the wear resistance also worse. As the hammer of the internal anti-wear performance was significantly lower than the surface, therefore, the larger the thickness of the hammer, the only reasonable means of casting and heat treatment process to improve this situation, but the means to improve the wear hammer performance is limited, the best way is to not change the kinetic energy and intensity of the hammer blow to the case of the hammerhead structure to optimize the design, one can improve the utilization of the hammer, the other can reduce the structure thermal properties, wear resistance to avoid the hammer down.